Automatic unlocking device for switch mechanisms.



No. 832,729. TATENTED OCT. 9, 1906. J. D. HILLIARD, JR. AUTOMATIG UNLOGKING DEVICE FOR SWITCH MECHANISMS.

APPLICATION FILED APB.20,1904.

' 2 SHEETSSEBET 1.

L z \I 5 Fig. I.

Fig.4.

(ULEnssses. Invention 4 WLLLLGPG Jr.

I may No. 832,729. PATENTED OCT. 9, 1906. J.'D. HILLIARD, J11.

AUTOMATIC UNLOGKING DEVICE FOR SWITCH MECHANISMS. APPLICATION FILED APE.20,1904.

2 SHEETS-SHEET 2.

Fig.5.

N E a? a as q Inventor". (Lhbncpsqs. John D. HLLLLcJrdJI".

UNITED STATES PATENT OFFICE.

JOHN H-ILLIARD, JR., OF GLENS FALLS, NEW YORK, ASSIGNOR TO GENERAL ELECTRIC COMPANY, A CORPORATION OF NEW YORK.

AUTOMATIC U NLOCKING DEVICE FOR SWITCH MECHANISMS.

Specification of Letters Patent.

' v Patented Oct. 9, 1906.

Application filed April 20. 1904. Serial No. 204,074-

' the machine to be connected be running at the same speed and in phase with the other machine or machines.

The object of my invention is to keep the switch locked until it is safe to closeit and ing theunlocking-solenoid, and Fig. 4 is a side elevation of the modified form of each used in Figs. 2 and 3 shown on a larger scale.

'The bus-bars 1, 2, and 3 are supposed to be conveying current generated by one or more machines, (not'shown,)- and it is desired to connect the generator 4 to said bars by means of the triple-poleswitch 5. Said switch is opened and closed by a hand-lever 6, connected with the switch-blades in any suitable manner, as by a connecting-rod 7 and elbow-lever 8. Adjacent to the lever is a solenoid 9, whose movable core is connected with a latch 10, preferably ivoted and adapted to engage with a shoul or 11 on the rod 7 and prevent it from being moved to close the swi.ch. Upon energizing the solenoid the latch is lifted. The solenoid is preferably controlled by a relay 9" in such a way that the solenoid is active when the relay is fully energized.

Referring now to Fig. 1, it will beseen that the machine-leads 1 2 3 are 0 en but that the switch-blade controlling t e lead 2 is shunted by a conductor 2", controlled by a switch 12 and containing one or more incandescent lam s 13. The switch-blade controlling the ead 3 is shunted by a conduc tor 3*, controlled by a switch 14 and containing the windings of the solenoid 9.

The operation is as follows: The switches 12 and 14 being closed, the machine 4 will sup-v ply current to the conductors. 2 and 3 so ong as it is out of phase with the current'in the bus-bars. The'lamps 13 will therefore flash, the relay 9 will raise its core, and thesolenoid 9 will lift the latch and lock the switch-rod; but as the machine a proaches synchronism the lam s' 13 will dar en, being connected to similar eads of the system, and when the lamps finally become dark and the hases in the solenoid-circuit and the bus ars coincide, and thus oppose each other,

the relay 9 will be denergized, opening the circuit of the solenoid 9, the latch 10 will drop, and the switch can be closed. The solenoid 9 may be fed by a otential transformer, as indicated, or by a ocal source.

In Fig. 2 the solenoid has two windings, one in a cross connection 2 3 between the machine-leads 2 3 and the other in a cross connection 2 3 between the similar busbars 2 3. Switches 15 16 control the cross connections. As the machine ap roaches synchronism the sum of the two uxes induced by these windings increases. until at the point' when the switch can be safel closed it becomes sufficient to lift the late and release the switch-rod 7. g The solenoid 9 is here shown, as also in Fig. 3, as directly included in the synchronizing-circuit. In practice it may be preferable to control it by a relay, as in Fig. 1, for increased sensitiveness of action.

In Fig. 3 a potential transformer 17 is introduced into each cross connection in order to reduce the voltage of the current flowing through the solenoid. By connecting the secon only one winding is necessarf on the solenoid. The secondary currents wil artially overlap and weaken each other Whl e the machine aries of these transformers in series.

too

is out of phase, but when 5 nchronism is reached the two currents wil coincide and will Isltrongly energize the-solenoid and lift the late I Fig. 4 shows thelock used in Figs. 2 and 3. The solenoid issupported by brackets 18 on an upright base- 19, through which the rod 7 passes and on which is pivoted the latch 10.

rod are preferably inclosed by a cover 20 to system. 3

prevent tampering with them. The lever 6 1s conveniently fulcrumed on an arm 21, projecting from the base 19 below the cover. I

In accordance with the What I claim as new, and desire to secure by Letters Patent of the United States, is 1. Thecombina'tion with a hand-operated switch free from closing bias for connecting an alternating-current machine with the busbars of a distribution system, of a lock for said switch, and anelectromagnet controlling said lock'and in circuit with said machine.

2. The. combination with a hand-operated switch free from closing bias for connectin an alternating-current machine in paralle with the bus-bars of a distribution system, of a lock for said switch, and an electroresponsive device controlling said lock and responsive to coinciding phases of the .machine and 3. The combination with a switch for connecting an alternatin ourrent machine in parallel with'the; busars of a distribution system, of a lock for said switch, an elect magnet'controlling said look, a cross connection between diflerent machine-leads, and a similar cross connection between similar busbars, both of said connections influencing the electromagnet.

4. The combination with a hand-operated switch free from closing'bias for connecting an alternating-current machine in parallel with the bus-bars of a distribution system, of

atent statutes 1' have described the princip e of operation of mg; invention, together with the ap aratus circuit.

a lock for said switch, an electromagnet con- I sai magnet.

5.. The combination with a switch for connecting an alternatin current mach1nc 1n parallel with the busars of a. distr1but1on (system, of cross connections between the machine-leads and the'bus-bars, a solenoid whose windings include'both'cross connections, and a lock for the switch controlled by said solenoid. I

6. The combination with a .solenoid, of a movable core, a, latch ivotally attached thereto, a rod having a s oulder with which said latch enga es, and a cover inclosi said latch and the s ouldered portion of sai rod.

7. In an alternating-current system, a lurality ofgeneratqrs, a co on distributioncircuit, a "hand-operated switch free from closing bias'for cutting into circuit one or more generators, means for normally disabling said switch from closure, and electrore- SPOIISLVG devices for permitting such closure when the phases coincide cross-connected between the machine-leads and the distribution- 8. The combination with a-hand-operated sw tch free from closing bias for connecting angltcrnating-current machine with the bus- -bars 3f the distribution-circuit; of a lock for 'said 'witcl. and an electromagnet controlling said lock and connected in shunt to said switch. In witn ss whereof I have hereunto set my hand this-8th day of April, 1904.

" JOHN D. HILLIARDJR.

Witnesses: J. M. SEAY,

, C. L. SWAN.- 

